The present invention relates to a device for dispensing a liquid from a collapsible container. The invention is particularly useful for dispensing infusion liquids, and is therefore described below with respect to this application, but it will be appreciated that the invention could advantageously be used in other applications as well.
Infusion devices, as commonly used in the medical field, frequently require that the infusion liquid be dispensed at a substantially constant pressure. One of the disadvantages of many known types of such devices, particularly the simpler ones, is that the infusion pressure does not remain substantially constant, but rather changes with the change in volume of the infusion bag occurring during the infusion operation. The known infusion assemblies, wherein such a substantially constant pressure is maintained, are generally of relatively complicated construction and therefore costly to produce.